A multiple technique approach is used to study YBa2 Cu 3O7 grown on SrTiO3 as a function of post‐deposition annealing temperature. X‐ray diffraction data are used to determine the relative amounts of a‐axis and c‐axis oriented growth. These results are compared to the surface morphology of the films observed by SEM. Secondary ion mass spectrometry (SIMS) is used to study the diffusion of substrate elements into the YBCO films as a function of post‐deposition annealing temperature. The data obtained from all these techniques are correlated to determine an optimized temperature for post‐deposition annealing. The results of this study show that the desired c‐axis oriented growth can be obtained with minimal diffusion of substrate elements into the film at annealing temperatures of 750 °C.